A light-sensitive material comprises a support and a light-sensitive layer provided thereon containing silver halide, a reducing agent and a polymerizable compound. An image is formed by imagewise exposing the light-sensitive material, and heating the light-sensitive material. A latent image of the silver halide is formed by the exposure. The polymerizable compound is polymerized within the area where the latent image has been formed by the heat development process. After the heat development process, the light-sensitive material is usually pressed on an image receiving material to transfer the unpolymerized polymerizable compound to the image receiving material. This image forming method is disclosed in U.S. Pat. No. 4,629,676 (European Patent Publication No. 0174634A2 and Japanese Patent Provisional Publications No. 61(1986)-69062 and No. 61(1986)-73145).
Another embodiment of the image forming methods is disclosed in Japanese Patent Provisional Publications No. 61(1986)-260241, No. 2(1990)-141756, No. 2(1990)-141757, No. 2(1990)-207254 and No. 2(1990)-262662. The contents of the former two publications are described in European Patent Provisional Publication No. 0202490A. In this embodiment, a polymerization inhibitor is formed from an oxidation product of a reducing agent within the area where the latent image of the silver halide has been formed.
In the above-mentioned image forming method, it is difficult to obtain a clear transferred image having a high maximum density without causing stain. The stain can be reduced when the temperature of the heat development process is low. However, the maximum density is remarkably reduced by the high temperature. Therefore, it is also difficult to form a clear image if the heat development conditions are changed.
By the way, the polymerizable compound used in the light-sensitive material preferably is an acrylate or methacrylate.
Examples of the acrylate disclosed in the prior art references include n-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, furfuryl acrylate, ethoxyethoxyethyl acrylate, tricyclodecanyloxyl acrylate, nonylphenyloxyethyl acrylate, 1,3-dioxolan acrylate, hexanediol diacrylate, butanediol diacrylate, neopentylglycol diacrylate, tricyclodecandimethylol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexacrylate, diacrylate of polyoxyethylenated bisphenol A, 2-(2-hydroxy-1,1-dimethylethyl)-5-hydroxymethyl-5-ethyl1,3-dioxane diacrylate, 2-(2-hydroxy-1,1-dimethylethyl)-5,5-dihydroxymethyl-1,3-dioxane triacrylat e, triacrylate of propyleneoxide addition product of trimethylolpropane, polyacrylate of hydroxypolyether, hexaacrylate of carprolactone addition product of dipentaerythritol, polyacrylate of hydroxypolyether, polyester acrylate and polyurethane acrylate.
Examples of the methacrylate disclosed in the prior art references include methyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, butanediol dimethacrylate, neopentylglycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate and dimethacrylate of polyoxyalkylenated bisphenol A.